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ananyo writes "Bioengineers have made an artificial jellyfish using silicone and muscle cells from a rat's heart. The synthetic creature, dubbed a medusoid, looks like a flower with eight petals. When placed in an electric field, it pulses and swims exactly like its living counterpart. The team now plans to build a medusoid using human heart cells. The researchers have filed a patent to use their design, or something similar, as a platform for testing drugs (abstract). 'You've got a heart drug?' says Kit Parker, a biophysicist at Harvard University in Cambridge, Massachusetts, who led the work. 'You let me put it on my jellyfish, and I'll tell you if it can improve the pumping.'" The video that accompanies the text is at once beautiful and creepy.

Well yes, thank, but no one was claiming this did away with all existing drug testing. This fills a gap: that is, what will actually happen if, all other things being equal, you introduced a drug to the cells of the heart? That answer can only currently be answered by human trials. This gives you data before you reach that stage.

It's a small part, but it's an important one. You need to check if a potential drug can make the muscle cell work differently (mostly for drugs targeting heart cells: pump stronger).A human heart could react in a different way. But on the other hand, this jelly fish would have a better reaction than a simple isolated cell on a petri dish.The petri dish cell is mostly only useful to test for basic molecular response (does the ion flux increase across the cell-wall transporter when the drug is bound to it ?)With platform like the jelly fish you can also test the effect - like cell contraction.

It's far from a new organism. So far it's not much different from a frog corpse that moves because it's being zapped.I doubt it self repairs itself (e.g. if you destroy one part, the other cells around will reproduce and rebuild what you destroyed). When the cells somehow help rebuild the new entity, then it is a new multicellular organism. When we've figured out how the cells figure out what and where to build, and control that, then we'll have made a lot of progress.

'You've got a heart drug?' says Kit Parker, a biophysicist at Harvard University in Cambridge, Massachusetts, who led the work. 'You let me put it on my jellyfish, and I'll tell you if it can improve the pumping.'"

They'll do that too. This just lets you see one important aspect of the drug's activity really clearly and let's you get a little quantitative about the effects too. Admittedly, the really cool thing isn't the application but that they've built something that moves like a jellyfish when you apply an electric field across it in water.

That must have been one desperate dalek. They are helpless outside of their travel machines, and no sane dalek would never leave one willingly except for medical attention or machine repair - which, to a dalek, are the same thing.

The jelly moves through the water. In the heart the water moves through the jelly. Same basic action. Imagine the same device being built using human cells, especially cells from the potential patient, this chimeric pump is a first step, perhaps a major step, in building a bioelectric replacement heart or even an auxiliary heart. They sussed that bioelectric pumps work by sending an electrochemical wave front through the tissue. In principal a jellyfish and a heart have a lot in common. Especially in some people.

There has been some research already that offers a potential there: Growing cells onto a temporary scaffold. It's still many years away from being able to grow a heart in a lab from a patient's own cells, but the possibility is there. Simpler organs are already in use that way - trachea, bladder, some others - but hearts are much more difficult. You'd still need a pacemaker though, an artificially grown heart isn't going to contain the required nerves to keep everything contracting in sync without one.

The nervous system is capable of speeding the main pacemaker, but that connection isn't necessary to keep the heart beating. And the pacemakers are redundant, set at different frequencies. The highest frequency pacemaker drives the rest; should it fail, the next slower one takes over.

Same thing though - that biology evolved to grow a tiny embryonic heart and slowly make it bigger. Forcing cells to grow into a new adult heart using a scaffold isn't going to get even those specialised muscle cells aren't going to end up in the right places.

is arguably the big problem of biology. As a student I had a two-hour discussion on an airplane on the subject with one of the professors at my school -- in 1973. The goal is nearer thirty years later, but far from being realized. The work with scaffolds and viruses is awesome. But until this problem is solved I agree that you would certainly have to stimulate your bio-synthetic heart with a pacemaker.

And, hey, I'm no spring chicken. Any biologists out there working on this better log off Slashdot and

I also understand that you need the scaffold to be somewhat flexible - those cells beat, and the movement is actually one of the signals determining differentiation. Not a huge problem for growing somewhat-misshapen rat hearts, but a serious issue for trying to replicate something as large as a human heart.

Finally! Science has found a way to bridge the gap between aquatic life outside of the vertebrates, and members of order rodentia. Soon, the seas will team with jellyrats, and sewers will overflow with rodentfish! A glorious day!

Dr. Ichthius will be very pleased. Yes. Very. Pleased.

Muahahahah!!!

(I decided to pass on the opportunity to write "Well, I for one WELCOME our new Jellyrat overlords...)

As a human being, this announcement is without a doubt extra creepy. However, as a scientist, it's fricking awesome! As a mad scientist, I'm giving it three thumbs up.

Takes a moment to get past the "we made an artificial jellyfish (WHY? Don't we have enough of those transparent, swimming, stinging masses of doom?)," and to get onto the real meat of the article: artificial hearts that can be used to test the effectiveness of various experimental drugs without putting human beings at risk.